A church described by former staff and congregation members as a "cult" is being investigated by the University of Arizona, reports the Arizona Star.

Faith Christian Church has operated at the University for 25 years and has founded a number of affiliated branches at other US universities.

It is facing the investigation because of a complaint made by the mother of a student who contacted university administrators because she was alarmed by a "radical" shift in her son's personality and behaviour since he joined the church.

"They get their members to believe that any questioning, any scrutiny, it's the devil," said Kathy Sullivan. "I want to get my son out of there. I want to do whatever I can to prevent other families from letting their children get in a situation like this."

The Arizona Star's investigators interviewed 21 former employees and church members and nine of their parents. According to the Star, there were reports of financial coercion, alienation from parents, public shaming of members and shunning of those who leave the church or question its leaders.

Some said that since leaving they have had therapy for panic attacks, depression, flashbacks and other symptoms of post-traumatic stress disorder.

Among the most disturbing reports is that church members were encouraged to spank their children, beginning with infants in a crib using the cardboard cover from a wire coat hanger. "They train you as a parent that, once the babies are eight weeks old, you have to lay them face down. If the baby raises its head, that's a sign of rebellion, so you smack them on the butt with the cardboard dowel," says Rachiel Morgan, who worked for the church until 2008.

The Star was told that once children started standing and walking, the cardboard covers were replaced by wooden spoons that sometimes left spoon-shaped bruises on toddlers' buttocks.

Another former staff member, Jeff Phillips, told blogger Warren Throckmorton that the techniques were taught to "drive out the rebellion" in the children. "The only way to recognise rebellion in a child that small is to place the child on his belly to put him to sleep," they were told. "If parents worried about infants suffocating or SIDS, they were told 'to live by faith and not worry that our baby would die in the crib if he was on his belly'."

The church is a member of the Evangelical Council for Financial Accountability, but has also faced questions about its financial practices. Members report excessive pressure to tithe their income and a gradual loss of control over their personal lives. 

The church has not responded publicly to requests for comment.